Closure valve for the outlet port of a pressure accumulator



' 2 Sheets-Sheet 1 INVENTOR .feamMefici efi f I 2 JTTORNEYJ April 7,1959 J. MERCIER CLOSURE VALVE FOR THE OUTLET PORT OF A PRESSUREACCUMULATOR Filed Dec. 9, 1953 April 1959 J. MERCIER 2,880,758

CLOSURE VALVE FOR THE OUTLET PORT OF A PRESSURE ACCUMULATOR 2Sheets-Sheet 2 Filed Dec. 9, 1953 T av, -T fi.

E if! -123 1/7 115 8 I26 Tq-Z 1Z5 /5 I 19 BY wax/RM ATTORNEYS CLOSUREVALVE FOR THE OUTLET PORT OF A PRESSURE ACCUMULATOR Jean Mercier, NewYork, N .Y.

Application December 9, 1953, Serial No. 397,241

6 Claims. (Cl. 138-30) This invention relates to the closure for theoutlet port of a container for fluid and more particularly to a'closurevalve for a pressure accumulator of the type having a rigid container tobe filled with fluids, usually oil and air under pressure and having adeformable partition .intervening between such fluids.

When oil is pumped into the outlet port of the container on one side ofthe partition, it will deform the latter and compress the air previouslycharged into the containeron the other' side of the partition. In use ofthe accumulator, a control valve in the line between the outlet port andthe hydraulic device to be operated, is

opened and the partition in expanding will force such oilfrom thecontainer through the closure valve.

Unless the closure valve remains open until substantially all the oil inthe container is expelled, the trapped oil will not be available foruseful purposes. Also where the partition when expanding is forcedagainst and extrudes past the closure valve, it is likely to become.

pinched or torn with resultant failure of the equipment.

Where, to retain the valve open so that substantially all of the oil maybe expelled from the container, a relatively strong spring is used toreact against the valve head, if such spring also keeps the valve openeven when the container is substantially empty, the partition may beextruded past the valve head with resultant injury thereto.

Where, to ensure that the valve head will close before thepartition canbe extruded, a relatively weak spring is used, then the expandingpartition, when it engages the valve head, will immediately overcome theforce of the spring and close the valve while the container is stillcharged with a considerable quantity of liquid. Furthermore, in theevent a large rate of flow of liquid is desired, during any short periodof time, such as, for example, to operate a hydraulic brake, the flow ofsuch fluid would result in a low pressure area beneath the valve headand a high pressure area in the container.

It is=accordingly among the objects of the invention to As a' result,the relatively weak spring would not be able to Patented Apr. 7, 1959 bythe partition in direction to close the valve, it provides aprogressively increasing force opposing the force causing suchcompression and thereupon when such compression or stroke exceeds .apredetermined amount it pro vides a progressively decreasing forceopposing the force causing such compression.

In the accompanying drawings in which are shown one or more of variouspossible embodiments of the several features of the invention,

Fig. 1 is a longitudinal sectional view of an accumulator having oneembodiment of the invention incorporated therewith,

Figs.v2, 3, 4, 5 and 6 are fragmentary sectional views similar to Fig. 1of other embodiments of the invention,

Fig. 7 is a view'similar to Fig. 6 in a-second position of operation,and

Fig. 8 is a graph illustrating the operation of the resilient meansutilized in the closure valve.

Referring now to Fig. 1 of the drawings, the pressure accumulatordesirably comprises a container or pressure vessel 11 preferably ofstrong rigid material such as steel, cast aluminum or the like, capableof withstanding high pressures. The container may be spherical orcylindrospherical as desired and has a deformable partition interveningbetween the gas inlet port 12 and the liquid outlet port 13 of thecontainer. Preferably the partition is a collapsible and expansible bag14 which desirably is provide a closure valve for the outlet port of apressure 1 partition in the container-can be extruded past such closurevalve.

According to the invention, the closure valve includes resilient meansagainst which the expanding partition will I react, said resilient meansbeing of the type such that over a predetermined range of itscompression or stroke, or tension applied thereto. caused by the forceexerted of resilient material such as rubber or synthetic plastic oflike physical characteristics, which in distended but substantiallyunstretched condition is smallerthan the:

may include a tubular member 16 positioned in said port. 7 Although anysuitable means may be used to mount the tubular member 16, it isdesirably so retained in port 13 that it may be removed therefromwithout likelihood of:

injury to the mechanic disassembling the accumulator. To this end theconstruction shown in Patent No. 2,469,- 171, dated May 3, 1949 ispreferred.

As shown, tubular member 16 desirably has an external annular flange 17at its inner end of smaller outside diameter than the diameter of port13 and defining an annular shoulder 18. A locking member, illustrativelya ring 21 of greater diameter than said port 13 and deformable to permitits insertion into said port, encompasses said, tubular member 16 and isseated onthe rim 22 of port 13, the inner diameter of said ring 21 beingless than the outer diameter of flange 17 so that said shoulder 18 mayseat on said ring. Encompassing said tubular member 16 and injuxtaposition to port 13 is a rubber gasket or seal ring 23 which serveseffectively to prevent leakage between port 13 and the side wall oftubular member 16 when a nut 24 is screwed on.the externally threadedportion of .tubular member 16-.

The construction thus far described is not per se claimed tion shown inFig. 1, the tubular member 16 has a trans-, verse wall 31 across itsinner end, which wall has an axial bore 32 as well as a plurality offluidpassageways 33 therethrough.

The inner end of member 16 is desirably beveled as at? 34 to form a seatfor the corresponding beveled edge 35 of a valve head 36 whichpreferably has a rounded top of stem 38 in bore 32.

Resilient means are provided normallyto urge the valve stem 38 and valvehead 36 into the container 11 so that the rim 35 of the valve head willbe spaced from the valve seat 34 to provide communication between theinterior of the container 11 and the bore 41 of tubular member 16.

Such resilient means comprises a spring of such type that it normallyexerts considerable force against the stem 33 to retain the valve headin open position, but after it has been compressed or stressed apredetermined amount the force exerted by the spring will be greatlyreduced.

In the embodiment shown in Fig. 1, the spring is a leaf 42 preferably ofspring steel and a pair of such springsare desirably provided, the lowerend 43 of each spring being positioned against an abutmentillustratively a-recess do in the wall of bore 41 on opposed sidesthereof and the upper end 45 of eachspring also being positioned againstan abutment or recess 46 in the lower end of valve stem 38.

The embodiment shown in Fig. 2 is similar to that shown in Fig. l andcorresponding parts have the same reference numerals primed.

In this embodiment, the bore 41' of tubular member 16 is of reduceddiameter at its inner end as at 47 defining an annular shoulder 4-8.Slidably mounted in bore 47 is a sleeve 49 which has a laterallyextending flange 51 at one end which may abut against shoulder 48. Theother end of the sleeve which will extend beyond the preferably flat,inner end 52 of the tubular member 16' when flange 51 is againstshoulder 48, is closed as at 53 and forms a valve head, and the sleeve49 adjacent its closed end has at least one opening or passageway 56-therethrough. This passageway normally provides communication betweenthe interior of container 11 and the bore 41' of tubular member 16'.

The sleeve 49 is urged inwardly to open position to expose passageway54, by a leaf spring 42' similar to those shown in Fig. I. The upper end56 of leaf spring 42 is retained in a recess 57 in the bottom of theclosed end 53 of the sleeve and the lower end 58 is retained in a recess59 in a plug 61 screwed into the bore 41, said plug having a pluralityof fluid passageways 62 there, through.

The embodiment shown in Fig. 3 is in many respects also identical tothat shown in Fig. l and corresponding parts have the same referencenumerals doubled primed.

The stem 38" of valve head 36" in addition to passing through the bore32" of transverse wall 31" also extends through the bore 63 of a secondtransverse wall 64 positioned in bore 41" beneath wall 31".

The valve head 36" of the embodiment shown in Fig. 3 is normallyretained oil its seat 34 by means of one or more Belleville washersprings 65 which encompass stem 38" and are positioned between wall 31"and valve head 36". The springs 65 are desirably positioned in opposedrelationship for addition of the force to be exerted by each spring.

"The Belleville washer springs function like the leaf springs 42 and 42in that they normally exert considerable force against the valve head36" to retain the latter in open position, but after they have beencompressed or stressed at predetermined amount, the force exerted by theBelleville washer springs will be greatly reduced.

In the embodiment shown in Fig. 4, the tubular member 71 is retained inthe port 72 of the container, preferably by the same means as that shownin Figs. 1 to 3.

Member 71 has a. plurality of passageways 73 leading from its inner end74 adjacent its periphery to an axial bore 75 therethrough. A concavemember or disc 76 preferably of spring steel, having: the samecharacteristics-as the leaf spring and Belleville washer springs ofFigs. 1 to 3 is affixed as by a screw 77 to such inner end, 743 so thatthe convex under-surface oi the disc is 4L against inner end 74. Thediameter ofdisc 76 is such that when the rim 78 thereof is moveddownwardly by the bladder, the passageways 73 will be closed.

In the embodiment shown in Fig. 5, the pressure accumulator comprises acontainer or pressure vessel 84 of steel, cast aluminum or the likewhich may be of any desired configuration and illustratively iscylindrospherical. The upper end of the container desirably has arelatively large opening 85 with a plug 86 aifixed therein which has agas inlet port 87.

The lower end of the container desirably has an elongated tubularportion 88, the bore 89 of which defines the liquid outlet port. Adeformable partition, preferably a collapsible and expansible bag 91 ofsuitable resilient material intervenes between the ports 87 and 89 andthe inlet 87 leads into the bag M.

To close the outlet port 89, a closure assembly 92 is provided, whichcomprisesa sleeve 93 slidably mounted in the reduced diameter portion94: at theinner end of bore 89. The sleet/e 93 has a valve head 95 atits inner end adapted to be moved against a seat 96 to seal the outletport,- and-the sleeve 93 adjacent said head has at least one opening orpassageway 97 therethrough. This passageway normally providescommunication between the interior of container 84 and the bore 89.

The sleeve 93 is urged inwardly to open position to expose passageway 97by leaf springs 98 similar to those shown in Fig. l. The upper ends 9hof each spring are positioned in a recess or abutment 101 in theundersurface of valve head 95, and the lower ends 102 of the springs arepositioned against an annular shoulder 103 formed by the upper end of afitting screwed in the lower end of tubular portion 88 The movement ofthe sleeve 93 into the container is desirably limited by a nut 104screwedon the threaded end 105 of the sleeve and which may abut againstshoulder 106.

The embodiment shown in Figs". 6 and 7 is substantially identical tothat shown in Fig. l except that the leaf springs 42 are replaced bycoil spring means 111 hav-' ing the same characteristics. This springmeans, which is known as a negative spring or Negator, is described indetail in- Product Engineering July 1949 issue and has thecharacteristics such that it will originally exert progressivelyincreasing force when first stressed and after being stressed apredetermined amount will exert a progressively decreasing force.

As shown in Figs. 6 and 7, the stem 112 of valve head 113 isslidablyrnounted in and extends beyond the bore 114 of the axial tubularextension 115 of a perforated Wall 116 positioned in tubular member 117.The coils 118 and 119 of the Negat'or 1111 are mounted on pins 121atfixed in the tubular member 117 with the intervemng run 122 of thespring 111 extending across the end 123' of tubular extension 115. Thevalve stem 11 2 is of reduced diameter at its free end 124' and extendsthrough an opening in run 122, a nut 125 screwed onthe threaded reducedend 124 retaining the stem and run 122 of the spring-together. I v

The bore at the free end 123 of extension H5 is of enlarged diameter asat 126 so that when fluid under pressure is initially forced into thecontainer and reacts against the valve head to move it inwardly, the run122 of spring 11 will enter such bore portion 126 as shown in Fig. 7 totake up the initial impact againstthe valve head thereby preventingshearing ofthe thread ofthe nutor the threaded end 124' of thevalvestein 1112;.

It is to be noted that the resilient members. in all of the embodimentsshown are normally under tension, so that they may function in desiredmanner.

The resilient members of the embodiments shown have the characteristicsclearly illustrated by the graph shown in Fig. 8-.

Thus when pressure i applied to the resilient members by the expandingbladder, as they are first compressed or stressed or placed undertension,.over a predetermined range measured along the abscissa 81 ofthe graph-to the point A, the force exerted by the resilient members torestrain closing of the valve will progressively increase an amountmeasuredalong the ordinate 82. Thereupon as the resilient members arefurther compressed or stressed or placed under tension, past the pointA, the force exerted by the resilient members will progressivelydecrease.

The resilient members are desirably originally compressed or stressed orplaced under tension to the position shown, for example, at B on thegraph in Fig. 5. Thus, a considerable force will be available to retainthe valve in open position.

Even if the rate of flow through the tubular members of any of theembodiments shown should be great, with resultant high differentialbetween the pressures on opposing sides of the valve, the force of thetensed resilient member will be suflicient to overcome such differentialand retain the valve open.

Referring specifically to Fig. 1, as the bladder progressively expandsand engages the valve head 36, the latter will not be moved until thebladder has expanded sufficiently to exert enough force against thevalve head 36 to overcome the counter force exerted by leaf springs 42.Thus, referring to Fig. 8, not until the force exerted by the bladderhas reached the point B will the valve head move.

At this time substantially all of the oil has been discharged from thecontainer 11 and with slight additional expansion of the bladder andfurther increase of the force exerted thereby, the valve head will movedownwardly compressing the springs 42 until they reach the point A onthe graph. With further expansion of the bladder and compression of thesprings 42 the counter force exerted by the springs 42 against the forceexerted by the bladder will start to decrease. Consequently, the greaterforce exerted by the bladder will quickly overcome the force exerted bythe springs 42 and the valve head 36 will seat almost immediately beforethe bladder can extrude therebeneath.

In view of the above explanation, the operation of the embodiments shownin Figs. 2, 3, 4, and 6 is readily apparent.

With the construction above described, a closure member is providedwhich will dependably retain the outlet port of a pressure accumulatoropen until substantially all of the oil is expelled therefrom regardlessof the rate of flow of the oil from the accumulator, yet with assurancethat when substantially all of such oil is discharged the outlet portwill be closed without likelihood of extrusion of the bladder.

As many changes could be made in the above equipment, and manyapparently widely different embodiments of this invention could be madewithout departing from the scope of the claims, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a pressure accumulator of the type having a rigid container and adeformable partition intervening between the inlet port and the outletport; the combination therewith of a closure member comprising a valveseat, a valve head slidably mounted with respect to said seat, the innerend of said valve head being adapted to be positioned in such containerto be engaged by such partition upon expansion thereof, and a leafspring reacting against said valve head normally to retain the latterspaced from said seat, said leaf spring being of the type that over apredetermined range of tension applied thereto provides a progressivelyincreasing force opposing the force exerted by the expanding partitionagainst said valve head and thereupon when such tension exceeds apredetermined amount, provides a progressively decreasing 'forceopposing the force exerted' by the expanding partition against the valvehead.

- 2. In a pressure accumulator of the type having a rigid container withan inlet port and a deformable partition intervening between said inletand outlet ports; the combination therewith of valve means comprising atubular member coaxial with said outlet port and having a valve seat atone end, a valve head adapted to be engaged by such partition uponexpansion of the latter to be moved against said seat to seal thelatter, and a l/Jaf spring forming part of said valve means reactingagainst said valve head normally to retain the latter spaced from saidseat, said leaf spring being of the type that over a predetermined rangeof tension applied thereto provides a progressively increasing forceopposing the force exerted by the expanding partition against said valvehead and thereupon when such tension exceeds a predetermined amount,provides a progressively decreasing force opposing the force exerted bythe expanding partition against the valve head.

3. The combination set forth in claim 2 in which said valve head has astem extending into said tubular member, said leaf spring has one endengaging said stem and fixed with respect thereto and its other endengaging said tubular member and fixed with respect thereto.

4. The combination recited in claim 3 in which said stern has anabutment at its lower end and said tubular member has an abutment in itswall located at a point longitudinally spaced from the position of thelower end of said stem when said valve head is seated and the ends ofthe leaf spring are positioned against the respective abutments.

5. The combination set forth in claim 2 in which said valve seat is atthe inner end of said tubular member, the latter having a wall adjacentsaid seat with an axial bore and with fluid passageways therethrough,said valve head having a stem slidingly mounted in said axial bore andextending through the latter, said stem having an abutment at its lowerend and said tubular member having abutments on opposed sides of thebore thereof longitudinally spaced from the position of the lower end ofthe valve stem when the valve head is seated, and a pair of leaf springsare provide each having one end positioned against the abutment on thevalve stem and their other ends positioned respectively against theabutments on said tubular member.

6. The combination set forth in claim 2 in which said tubular member hasa reduced bore diameter at its inner end defining a shoulder, a sleeveis slidably mounted in said reduced diameter bore, the inner end of thesleeve being closed and defining the valve head, the other end of thesleeve having a lateral protrusion adapted to engage said shoulder, theclosed end of said sleeve extending beyond the inner end of said tubularmember when said References Cited in the file of this patent UNITEDSTATES PATENTS 1,001,510 Curbey Aug. 22, 1911 2,106,775 Trask Feb. 1,1938 2,162,719 Hay Jan. 20, 1939 2,308,475 Fawkes Jan. 12, 19432,325,193 Nutt July 27, 1943 2,331,921 Mercier Oct. 19, 1943 (Otherreferences on following page) wanin 8 :7 SfTATES MTENTE? 72,251 GreatBritain fin; Spt. 15, 1 937 2,345,124 Huberta Mar. 28 1944 588'004 GreatBritain May 1947 2,647,743 Aug 4 1953 2,659,391 Nov. 17 1953 .7 2 744743 v, May 8, 955 5 Plate Sprmg Deslgn, Product Englneering, 0ctober 46-v r FOREiGN PATENTS Ifleggtive Spring, Product Engineering, July 1949,267,920 Germany bhnn-mmflr. Disc. 3, 191a-

